The Influence of Induced Hypoxaemia on the Carbohydrate Metabolism of the Liver with Special Reference to General and Hepatic Circulations : CLINICAL PATHO-PHYSIOLOGICAL STUDIES BY THE HEPATIC VENOUS CATHETERIZATION METHOD

Abstract

Carbohydrate metabolism of the liver in a resting and fasting condition (Part I), and during induced hypoxaemia by 10% O2 gas inhalation (Part II), was studied in man by the hepatic venous catheterization method.1) Studies in Part I revealed that in the patients with hepatic diseases, there were a functional decrease in the hepatic mechanism for the blood sugar regulation, reduction in the glucose releasing ability of the liver and impairment of the hepatic lactate and pyruvate metabolism. About half of the patients with non-severe types of pulmonary tuberculosis showed abnormalities in carbohydrate metabolism of the liver, suggesting hepatic disturbance.Studies under induced hypoxaemia in Part II revealed that, in the normal subjects, the amount of hepatic glucose release was increased during the induced hypoxaemia, and the amounts of hepatic uptake of lactate and pyruvate were increased. In patients with hepatic disturbances, including those with pulmonary tuberculosis, the studies with hypoxaemia made the various abnormalities of the carbohydrate metabolism noted above more apparent and easy to understand.2) It was found that the amount of glucose supply to the liver regulates the amount of glucose release out of the liver. During the hypoxaemia the organism must cope with an increased extrahepatic demand for glucose as the result of increased anaerobic glycolysis, and adapt to the changed cardiac output. To this end the following sequence of events seem to take place ; an elevation of the hepatic inhibition-threshold of the glucose supply (as irritation) to the glucose release (as reaction) → increased glucose release out of the liver → increased arterial blood glucose concentration → increased glucose supply to the whole body, especially to main glucose consuming organs.In the cases with hepatic disturbances, this hepatic regulation of the blood sugar was reduced.